From: Chapple, Peter (peterc@petermac.unimelb.edu.au)
Date: Wed Jul 01 1998 - 06:06:35 EST
I haven't seen many responses to this case on the list (has my mailer
been letting me down ??). It seems quite interesting and worthy of
comment to me :-)
We perform all our gating for clinical samples using the CD34 vs SS
gating strategy. From a quick glance at the CD45/SS plot from Marc's
case, I would have suggested that his primary gate contains essentially
only immature myeloid cells (metamyelocytes etc.). There a very few
lymphoid cells and nothing to see in the locations where I would expect
to find blast cells (I admit that the "location" of blasts is highly
variable - but we don't expect see them so far over to the right hand
side). If I'm right on this point then a white count of >100 x 10^9/L
with predominantly myeloid precurors (and few if any blasts) would point
one in the general direction of CML or a myeloid leukemoid reaction.
There appear to be few cells in the monocytic region - so I would be
reluctant to include CMML in the differential Dx (until I saw the
blood/bm films)... although the patient's age and history are
appropriate.
This hypothesis is consistent with the markers Marc found to be positive
on these cells (CD13, CD15, CD33, MPO, Lactoferrin (in the neutrophils),
?? CD38 - can grow on anything !)
In cases like this flow cytometry is not usually helpful in the Dx (not
helpful enough to justify the cost at any rate) - I expect that Marc
will tell us that a quick look at the blood film could have saved him
the time and cost of the antibodies. The classical reference for this
methodology is by Gregory Stelzer in Clinical Cytometry Mar 1993, it
nicely shows the CD45/SS "footprint" with the location of the various
cell types.
Peter Chapple
Melbourne AUSTRALIA
>Greetings,
>Apologies to non-clinical types and to those without easy access to a
web browser.
>I submit this case for your review and comments. It is an excellent
example of the need to consider flow cytometry data in the
>context of accompanying laboratory data. At this time I will not
include any of that data, but instead will solicit
>opinions as to what one might expect to observe morphologically, and/or
any further staining that might be indicated.
>The specimen was a bone marrow aspirate from a 73 year old male with a
4 year history of anemia, who presented
>with a white count in excess of 100,000 cells per cubic mm. It was
received late on a Friday afternoon :*(, such that
>immunophenotyping was performed immediately, without waiting to examine
Wright-stained smears before proceeding.
>To review the cytometric data, please point your browser to:
>http://130.189.200.66/case/
>I will wait a week then post additional information pertinent to the
case.
>Respectfully submitted,
>Marc Langweiler
>-- End --
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